This invention relates to the art of material handling and, more particularly, to a displaceable liner arrangement for unloading an open top receptacle.
The present invention finds particular utility in connection with the unloading of an open top railway car and, accordingly, is disclosed and described in detail hereinafter in connection with such use. However, it will be appreciated that the invention is applicable to the unloading of wheel supported receptacles other than railway cars, and to the unloading of receptacles other than wheel supported receptacles.
The lateral unloading of open top wheel supported receptacles through the use of a liner in the receptacle having one end of the liner fixed to a side wall of the receptacle and the other end displaceable upwardly of the receptacle to achieve unloading is known as shown, for example, in U.S. Pat. Nos. 2,573,584 to Le Tourneau and 3,484,850 to Rodrigue. In such prior art arrangements, the liner is a unitary component, whereby the entire load within the receptacle is elevated and displaced therefrom at the same time during the unloading operation. Such simultaneous displacement of the entire contents requires both the provision of a liner having sufficient structural integrity to support the load and the use of structurally complex and/or large and expensive heavy duty equipment to achieve displacement of the liner and the load thereon during an unloading operation. Accordingly, such liner components and liner arrangements are undesirably expensive to construct, and the equipment or mechanisms for displacing the liners during an unloading operation are undesirably large, expensive and/or complex in structure.
It has also been proposed heretofore, as shown in U.S. Pat. No. 2,662,650 to Russell, to sequentially unload portions of an open top trailer receptacle in the direction rearwardly thereof through the use of a plurality of belts disposed in the receptacle lengthwise thereof and in overlapping relationship so as to divide the receptacle into compartments. The receptacle is unloaded by sequentially drawing the belts upwardly and rearwardly of the receptacle. While this belt arrangement overcomes the requirement for a single belt or liner component to bear the entire weight of the contents of a receptacle during an unloading operation, there are several disadvantages attendant to the structural arrangement of the belts and to the manipulation thereof to unload a receptacle. In this respect, for example, the succeeding portions of material unloaded from the receptacle are discharged at the same point at the rear of the receptacle and across the width thereof, whereby each belt must be removed or care taken otherwise to prevent the succeeding portions of material from being displaced onto or against the preceding belts. Further, regardless of whether the Russell belt arrangement is provided to empty a receptacle longitudinally or laterally thereof, efficient use is not made of the belt material, thus rendering the arrangement unnecessarily expensive. More importantly, the Russell belt arrangement requires the pre-forming of bins in the receptacle for the respective portions of the material loaded therein. Further, sequential filling of such bins from the rear end of the receptacle is necessary to prevent distortion of the upwardly extending portions of the belt material which would occur in the absence of such sequential loading. Such distortion would change the bin configuration and provide for unequal amounts of material in the bins and, thus, unequal load distribution on the belts during unloading displacement thereof. Such pre-forming of the bins and sequential filling thereof is time consuming and thus expensive and inefficient in connection with use of the unloading arrangement. Further disadvantage results from the fact that opposite sides of the belt material forming the bin particles are subjected to undesirable wear and potential damage by the imposition of forces and stresses in opposite directions thereagainst by the material in the adjacent bins.